1. Field of the Invention
The present invention relates to an improve and advanced system which is capable fo creating a desired three-dimensional form or modifying its once-created three-dimensional form in the fields of CAD (Computer Aided Design) and/or CAM (Computer Aided Manufacturing), NC machine tool, computer graphics, computer vision and other similar applications.
2. Description of the Prior Art
In the fields of CAD, CAM, NC machine tools, computer vision, computer graphics and the like, conventionally there have been well known three types of modellings to express a desire or predetermined form; that is, they are a wire frame modeller, a surface modeller, and a solid modeller.
In brief, with the conventional wire frame modeller, the above-mentioned kinds of forms can be expressed by using constructed points which are roughly populated as a finite type of a set which has lower density.
In case when the surface modeller is used, such kinds of forms can also be expressed by the same type of a set which has higher density.
In these cases, the two modellers of the above type can be performed by the way of estimating the lacked points among the given points obtained so as to express the form, that is, by means of interpolation operation based on the functional approximation.
The solid modeller piles up simple or primitive forms obtained as the typical sets in which the points are densely populated in a manner similar to a building-blocks-work to express a predetermined form. Each of these three conventional methods features a function to be able to express forms for solid bodies.
However, when used to express a three-dimensional form, the above-mentioned three conventional methods each lack in flexibility of expression so that they are unable to perform their functions sufficiently. Also, it well known that a form expression is one embodiment of a form producing/finishing process, while a form creation is also another one embodiment of the same process. All of the above-mentioned three conventional modellings, however, are found incapable of performing a continuous and throughout processing operation between these two embodiments.
For example, when the prior art solid modeller is used, it is true that some of three-dimensional forms can be expressed by means of combination of simple forms, but the solid model method is inherently unable to provide a free and detailed expression of such three dimensional forms. Thus, it can be naturally said that it is almost impossible to carry out a continuous and throughout processing operation from its expression step to its form creation step.